MONO-ENERGETIC NEUTRAL BEAM ACTIVATED CHEMICAL PROCESSING SYSTEM AND METHOD OF USING

• US 20090236314A1
• Filed: 03/21/2008
• Published: 09/24/2009
• Est. Priority Date: 03/21/2008
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Chen, Lee
• Granted Patent: US 9,520,275 B2
• Time in Patent Office: Days
• US Class Current: 216/67
• CPC Class Codes: H01J 2237/3341 Reactive etching
• CPC Class Codes: H01J 37/32027 DC powered
• CPC Class Codes: H01J 37/32091 the radio frequency energy being capacitively coupled to the plasma
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32357 Generation remote from the workpiece, e.g. down-stream
• CPC Class Codes: H01J 37/32422 Arrangement for selecting ions or species in the plasma
• CPC Class Codes: H01J 37/3244 Gas supply means
• CPC Class Codes: H01J 37/3255 Material
• CPC Class Codes: H01L 21/3065 Plasma etching; Reactive-ion etching

Abstract

A chemical processing system and a method of using the chemical processing system to treat a substrate with a mono-energetic space-charge neutralized neutral beam-activated chemical process is described. The chemical processing system comprises a first plasma chamber for forming a first plasma at a first plasma potential, and a second plasma chamber for forming a second plasma at a second plasma potential greater than the first plasma potential, wherein the second plasma is formed using electron flux from the first plasma. Further, the chemical processing system comprises a substrate holder configured to position a substrate in the second plasma chamber.

Claims

1. A chemical processing system configured to treat a substrate, comprising:

a plasma generation chamber comprising a first plasma region configured to receive a first process gas at a first pressure;

a process chamber comprising a second plasma region disposed downstream of said first plasma region and configured to receive said first process gas from said first plasma region at a second pressure;

a first gas injection system coupled to said plasma generation chamber and configured to introduce said first process gas to said first plasma region;

a plasma generation system coupled to said plasma generation chamber and configured to generate a first plasma at a first plasma potential in said first plasma region from said first process gas;

a separation member disposed between said first plasma region and said second plasma region, wherein said separation member comprises one or more openings configured to allow an electron flux from said first plasma region to said second plasma region to form a second plasma at a second plasma potential;

a bias electrode system coupled to said process chamber and configured to elevate said second plasma potential above said first plasma potential in order to control said electron flux;

a substrate holder coupled to said process chamber and configured to support said substrate proximate said second plasma region; and

a vacuum pumping system coupled to said process chamber and configured to pump said second plasma region in said process chamber.

2. The chemical processing system of claim 1, further comprising:

a second gas injection system coupled to said process chamber and configured to introduce a second process gas to said second plasma region.

3. The chemical processing system of claim 1, wherein said plasma generation system comprises an inductive coil configured to inductively couple power from a power source to said first process gas in said first plasma region.

4. The chemical processing system of claim 1, wherein said plasma generation system comprises a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, a transformer coupled plasma (TCP) source, a surface wave plasma source, a helicon wave plasma source, or an electron cyclotron resonance (ECR) plasma source, or a combination of two or more thereof.

5. The chemical processing system of claim 1, wherein said plasma generation chamber comprises at least one direct current (DC) conductive ground electrode having a conductive surface in contact with said first plasma, and wherein said at least one DC conductive ground electrode is coupled to DC ground.

6. The chemical processing system of claim 5, wherein said at least one DC conductive ground electrode comprises a doped silicon electrode.

7. The chemical processing system of claim 5, wherein said conductive surface of said at least one DC conductive ground electrode comprises a surface area in contact with said first plasma greater than any other surface area in contact with said first plasma.

8. The chemical processing system of claim 1, wherein said separation member is composed of a dielectric material.

9. The chemical processing system of claim 1, wherein one or more of said one or more openings in said separation member comprises a diameter greater than or equal to a Debye length.

10. The chemical processing system of claim 1, wherein said bias electrode system comprises at least one DC conductive bias electrode having a conductive surface in contact with said second plasma, and wherein said at least one DC conductive bias electrode is coupled to a DC voltage source.

11. The chemical processing system of claim 10, wherein said at least one DC conductive bias electrode comprises a doped silicon electrode.

12. The chemical processing system of claim 10, wherein said DC voltage source is configured to bias said at least one DC conductive bias electrode with a DC voltage ranging from about 50 V to about 5000V.

13. The chemical processing system of claim 10, wherein said process chamber comprises:

a chamber housing member that is fabricated from a DC conductive material and is coupled to DC ground;

a liner member coupled to said chamber housing member that is fabricated from a dielectric material and is configured to electrically insulate said chamber housing member from said second plasma;

an electrical feed-through that is configured to allow electrical connection to said at least one DC conductive bias electrode; and

an electrode insulator disposed between said at least one DC conductive bias electrode and said chamber housing member and configured to electrically insulate said at least one DC conductive bias electrode from said chamber housing member.

14. The chemical processing system of claim 1, wherein said substrate holder is coupled to DC ground, and wherein said substrate is at DC ground or floating ground.

15. The chemical processing system of claim 1, further comprising:

a controller coupled to said plasma generation system, said bias electrode system, said process chamber, said first gas injection system, said substrate holder, and said vacuum pumping system, and configured to adjust or control said second plasma by varying at least one of a power coupled by said plasma generation system to said first process gas in said first plasma region, a DC voltage coupled to said second plasma by said bias electrode system, a composition of said first process gas coupled to said plasma generation chamber, a flow rate of said first process gas coupled to said plasma generation chamber, a pumping speed coupled to said process chamber, or a temperature of said substrate, or a combination of one or more thereof.

16. A chemical processing system configured to treat a substrate, comprising:

a first plasma chamber for forming a first plasma at a first plasma potential;

a second plasma chamber for forming a second plasma at a second plasma potential greater than said first plasma potential, wherein said second plasma is formed using electron flux from said first plasma; and

a substrate holder configured to position a substrate in said second plasma chamber.

17. The chemical processing system of claim 16, wherein said first plasma is driven by a first boundary at DC ground voltage, and wherein said second plasma is driven by a second boundary at a DC bias voltage.

18. The chemical processing system of claim 16, wherein said substrate holder is coupled to DC ground, and wherein said substrate is at DC ground or floating ground.

19. The chemical processing system of claim 16, wherein said first plasma chamber comprises at least one DC conductive ground electrode having a conductive surface in contact with said first plasma, and wherein said at least one DC conductive ground electrode is coupled to DC ground.

20. The chemical processing system of claim 16, further comprising:

a separation member disposed between said first plasma chamber and said second plasma chamber, wherein said separation member comprises one or more openings configured to allow said electron flux from said first plasma to said second plasma, and wherein said separation member is composed of a dielectric material.

21. The chemical processing system of claim 16, wherein said second chamber region comprises at least one DC conductive bias electrode having a conductive surface in contact with said second plasma, and wherein said at least one DC conductive bias electrode is coupled to a DC voltage source.

22. A method for treating a substrate, comprising:

disposing said substrate in a process chamber configured to treat said substrate with plasma;

forming a first plasma in a first plasma region at a first plasma potential;

forming a second plasma in a second plasma region at a second plasma potential using electron flux from said first plasma region;

elevating said second plasma potential above said first plasma potential to control said electron flux;

controlling a pressure in said process chamber; and

exposing said substrate to said second plasma.

23. The method of claim 22, wherein said exposing said substrate to said second plasma comprises exposing said substrate to a mono-energetic space-charge neutralized neutral beam activated chemical process.